title: Anti-angiogenic activity and intracellular distribution of epigallocatechin-3-gallate analogs.
abstract: Angiogenesis, a process of construction of new blood capillaries, is crucial for tumor progression and metastasis. Our previous studies demonstrated that a component of green tea, epigallocatechin-3-gallate (EGCG), suppressed angiogenesis and subsequent tumor growth. In this study, to elucidate the detailed mechanism of the anti-angiogenic effect of EGCG and to enhance the antiangiogenic activity of EGCG, we designed and synthesized EGCG derivatives and examined their biological effect and intracellular localization in human umbilical vein endothelial cells (HUVECs). EGCG derivatives aminopentyl dideoxyEGCG and aminopentyl dideoxygallocatechin-3-gallate (cis-APDOEGCG and trans-APDOEGCG) had an enhanced inhibitory effect on the proliferation when used at more than 30 µM. To elucidate antiangiogenic effect of EGCG, we used a 1 µM concentration for subsequent experiments where no effect on proliferation was observed. These EGCG derivatives showed a stronger inhibitory effect on migration, invasion, and tube formation by HUVECs than the non-derivatized EGCG. Furthermore, the derivatives induced a change in the distribution of F-actin and subsequent morphology of the HUVECs. Next, we synthesized fluorescent TokyoGreen-conjugated EGCG derivative (EGCG-TG) and observed the distribution in HUVECs under a confocal laser scanning microscope. Abundant fluorescence was observed in the cells after a 3-h incubation, and was localized in mitochondria as well as in cytoplasm. These results suggest that EGCG was incorporated into the HUVECs, that a portion of it entered into their mitochondria.
authors.affiliation: Department of Medical Biochemistry, Graduate School of Pharmaceutical Sciences, University of Shizuoka, Japan.
authors.forename: Suratsawadee
authors.initials: S
authors.lastname: Piyaviriyakul
authors.forename: Kosuke
authors.initials: K
authors.lastname: Shimizu
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Asakawa
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kan
authors.forename: Pongpun
authors.initials: P
authors.lastname: Siripong
authors.forename: Naoto
authors.initials: N
authors.lastname: Oku
mesh_terms: D000199:Actins / Q000378:metabolism; D020533:Angiogenesis Inhibitors / Q000138:chemical synthesis / Q000494:pharmacology* / Q000627:therapeutic use; D001692:Biological Transport; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology / Q000627:therapeutic use; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003593:Cytoplasm / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008928:Mitochondria / Q000378:metabolism*; D009389:Neovascularization, Pathologic / Q000517:prevention & control; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D000199:Actins; D020533:Angiogenesis Inhibitors; D010936:Plant Extracts; D002392:Catechin; C045651:epigallocatechin gallate